Consider the clinical trial of depression drugs in Example 2.1.4. Suppose that a patient is selected at random from the 150 patients in that study and we record Y, an indicator of the treatment group for that patient, and X, an indicator of whether or not the patient relapsed. Table 3.3 contains the joint p.f. of X and Y.
a. Calculate the probability that a patient selected at random from this study used Lithium (either alone or in combination with Imipramine) and did not relapse.
b. Calculate the probability that the patient had a relapse (without regard to the treatment group).